Dental installations often comprise cannula holders which are fixed to the end of a pipe connected to a suction means and on which is fitted a suction cannula, which is disposable or sterilizable, whose end is introduced into the mouth in order to suck out the liquids and debris.
Suction instruments placed in the mouth are known, which are combined with cleaning means which send a stream of atomized water or a jet of air into the mouth.
Dental instruments for cleaning are also known, which are associated with an optical fiber which illuminates the interior of the mouth
U.S. Pat. No. 3,727,310 to Baker describes suction cannulae for dental use which comprise a hollow cannula in the form of a pistol grip equipped with a longitudinal conduit maintained under depression and, in addition, with two small conduits which are housed in the wall of the cannula and which convey water and compressed air, respectively. The cannula comprises a removable nozzle.
European Patent Application No. 138,119 Siemens describes a dental spray grip which comprises a bent grip on which is fitted a removable nozzle which may rotate slightly on its axis.
The grip comprises air and water conduits and electrical conductors which supply an electric lamp placed at the center of a bore in which the removable nozzle is fitted.
The removable nozzle comprises an axial conduit which conveys air. It comprises a small conduit which conveys water, of which the front end is disposed at the center of the axial air conduit. It comprises a light conductor which is disposed at the center of the rear part of the axial air conductor and on the periphery of the front, end thereof.
The instrument described in the patent to Siemens is a cleaning apparatus which does not aspirate,
European Patent Application No. 022,150 to Pisanu describes an instrument for cleaning by spraying and suction intended more particularly for dental care. This instrument is connected to a grip which is placed at the end of a flexible suction tube. It comprises a bent or straight suction cannula . It comprises a small tube housed inside the suction conduit of the cannula and at the center of the distal end thereof. This tube may convey air, a liquid or a mixture of the two.
The cannula which is connected to the small tube conveying the mixture of air and water cannot rotate about its axis.
French Pat. No. 449,995 to Firma et al. describes instruments which may be introduced into cavities in the human body and which comprise two tubes between which are disposed optical fibers for illuminating the operative field. The central tube may serve to aspirate foreign bodies, to introduce a handling device or to inject a liquid or a gas.
U.S. Pat. No. 3,208,145 describes suction instruments for dental use comprising two small air and water tubes, placed outside the instrument.
U.S. Pat. No. 3,624,907 Brass et al. describes dental instruments intended for cleaning the tooth root canals. These instruments comprise at their end a needle for injection of liquid which is placed at the centre of a suction nozzle.
The problem that the invention is seeking to solve is that of providing suction-cannula -holder instruments which can be fitted on the standard cannula -holders often equipping dental surgeries and which may receive suction cannulae comprising means for illuminating the interior of the mouth, means for washing by a stream of water, atomized or not, and drying means incorporated in the cannula which leave the suction canal of the cannula free and which do not hinder the freedom of the latter to pivot about its axis.